title: Crystal structure of the arginine repressor protein in complex with the DNA operator from Mycobacterium tuberculosis.
abstract: The arginine repressor (ArgR) from Mycobacterium tuberculosis (Mtb) is a gene product encoded by the open reading frame Rv1657. It regulates the L-arginine concentration in cells by interacting with ARG boxes in the promoter regions of the arginine biosynthesis and catabolism operons. Here we present a 2.5-A structure of MtbArgR in complex with a 16-bp DNA operator in the absence of arginine. A biological trimer of the protein-DNA complex is formed via the crystallographic 3-fold symmetry axis. The N-terminal domain of MtbArgR has a winged helix-turn-helix motif that binds to the major groove of the DNA. This structure shows that, in the absence of arginine, the ArgR trimer can bind three ARG box half-sites. It also reveals the structure of the whole MtbArgR molecule itself containing both N-terminal and C-terminal domains.
authors.affiliation: Group in Protein Structure and Function, Department of Biochemistry, University of Alberta, 431 Medical Sciences Building, Edmonton, Alberta, Canada T6G 2H7.
authors.forename: Leonid T
authors.initials: LT
authors.lastname: Cherney
authors.forename: Maia M
authors.initials: MM
authors.lastname: Cherney
authors.forename: Craig R
authors.initials: CR
authors.lastname: Garen
authors.forename: George J
authors.initials: GJ
authors.lastname: Lu
authors.forename: Michael N G
authors.initials: MN
authors.lastname: James
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004269:DNA, Bacterial / Q000737:chemistry* / Q000378:metabolism; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000737:chemistry* / Q000235:genetics*; D009875:Operator Regions, Genetic / Q000235:genetics*; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D012097:Repressor Proteins / Q000737:chemistry*; D055672:Static Electricity
chemical_list: C087018:ArgR protein, Bacteria; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012097:Repressor Proteins